Cambridge IGCSE Science - Combined 0653 — 2010 Oct/Nov Paper 3 · Variant 2

This document consists of 20 printed pages. IB10 11_0653_32/5RP © UCLES 2010 [Turn over *2322172427* For Examiner's Use 1 2 3 4 5 6 7 8 9 Total UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education COMBINED SCIENCE 0653/32 Paper 3 (Extended) October/November 2010 1 hour 15 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs, tables or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. A copy of the Periodic Table is printed on page 20. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. www.XtremePapers.com

2 © UCLES 2010 0653/32/O/N/10 For Examiner's Use 1 Fig. 1.1 shows some stages in the formation of a human fetus. ball of cells fetus zygote egg cell sperm cell amnion amniotic fluid Fig. 1.1 (a) Most human cells contain 46 chromosomes, but egg cells and sperm cells contain only 23 chromosomes each. Suggest a reason for this. [1] (b) Name the part of the reproductive system in which each of these events takes place. (i) Eggs are produced. [1] (ii) Fertilisation takes place. [1] (c) Describe the function of the amnion. [2]

3 © UCLES 2010 0653/32/O/N/10 [Turn over For Examiner's Use (d) A disease called thalassaemia is caused by a person's genes. The haemoglobin gene has two alleles, T and t. A person with the alleles tt has thalassaemia, but a person with alleles Tt does not. (i) State which allele, T or t, is dominant. Explain your answer. allele explanation [1] (ii) Complete the genetic diagram to show how two parents who do not have thalassaemia could have a child with thalassaemia. phenotypes of parents genotypes of parents gametes man without thalassaemia Tt and woman without thalassaemia … and gametes from woman gametes from man [4] (iii) Thalassaemia reduces the amount of normal haemoglobin in a person’s blood. Explain why someone with thalassaemia often does not have the energy to do vigorous exercise. [2]

4 © UCLES 2010 0653/32/O/N/10 For Examiner's Use 2 (a) Fig. 2.1 shows apparatus used in the electrolysis of copper chloride solution. copper chloride solution d.c. power supply test-tube electrolysis cell anode cathode Fig. 2.1 (i) Describe what is observed at the cathode. [1] (ii) Chloride ions have a single negative electrical charge, Cl -. For every copper ion in the solution, two chloride ions are present. Deduce the electrical charge of a copper ion. Show how you obtained your answer. [2]

5 © UCLES 2010 0653/32/O/N/10 [Turn over For Examiner's Use (iii) Fig. 2.2 shows diagrams of two particles, L and M. Each of these particles have 17 protons in their nucleus. Cl particle L × × × × × × × × × × × × × × × × × × Cl particle M 18 electrons 17 electrons × × × × × × × × × × × × × × × × × Fig. 2.2 State and explain which one of these particles, L or M, moves towards the anode during electrolysis. particle explanation [2] (iv) The bubbles of gas which rise from the anode contain diatomic molecules of chlorine. Complete the bonding diagram below to show how the outer electrons are arranged in a chlorine molecule. Cl Cl [2]

6 © UCLES 2010 0653/32/O/N/10 For Examiner's Use (b) The apparatus shown in Fig. 2.3 can be used to react lead oxide, PbO, and carbon. strong heat mixture of lead oxide and powdered carbon glass rod drop of limewater Fig. 2.3 When the mixture is heated, a redox reaction occurs in which lead oxide is reduced. The drop of limewater suspended on the glass rod turns cloudy. (i) Name the gas which is produced in this redox reaction. [1] (ii) Suggest the balanced symbolic equation for the redox reaction between lead oxide and carbon. [2]

7 © UCLES 2010 0653/32/O/N/10 [Turn over For Examiner's Use 3 (a) (i) Complete Table 3.1 to show the properties of alpha, beta and gamma radiations. Table 3.1 description charge range in air ionising ability alpha positive 5 cm very strong beta electron 50 cm gamma electromagnetic wave many kilometres weak [4] (ii) Many people have smoke detectors in their houses. Smoke detectors contain a radioactive source which emits alpha radiation. Explain why the alpha radiation from the smoke detector is not dangerous to people living in the house. [1]

8 © UCLES 2010 0653/32/O/N/10 For Examiner's Use (b) A scientist uses a Geiger counter to measure the radiation from a radioactive source. She records the results every hour. Fig. 3.1 shows the graph of her results. 0 5 10 15 20 25 200 180 160 140 120 100 80 60 40 20 0 time / hours reading on Geiger counter / counts per second Fig. 3.1 Calculate the half-life of the radioactive source. Show your working. [2]

9 © UCLES 2010 0653/32/O/N/10 [Turn over For Examiner's Use 4 Soya beans are an important crop in many tropical and subtropical countries, because they contain a lot of protein. (a) A farmer grows soya beans in a field on a steep slope. Describe two things the farmer could do to reduce the risk of soil erosion. 1 2 [2] (b) Soya beans and other crops are often attacked by aphids and other insect pests. Farmers may use pesticides or biological control to kill the pests. (i) Describe one advantage and one disadvantage of using pesticides, rather than biological control, to control pests of crops. advantage disadvantage [2] (ii) State what is meant by a systemic pesticide and explain one advantage of using a systemic pesticide rather than a contact pesticide. meaning advantage [2]

10 © UCLES 2010 0653/32/O/N/10 For Examiner's Use 5 (a) Fig. 5.1 shows a circuit built by a student. J K L A B two-way switch Fig. 5.1 (i) The switch is at position B. Which lamps will be lit? [1] (ii) The switch is then moved to position A. What happens to lamps J, K and L? lamp J lamp K lamp L [2] (b) The student has six resistors as shown in Fig. 5.2. 4 Ω 8 Ω 12 Ω 4 Ω 8 Ω 12 Ω Fig. 5.2 Explain how he can combine two of these resistors to get a total resistance of 6 ohms. [3]

11 © UCLES 2010 0653/32/O/N/10 [Turn over For Examiner's Use (c) Fig. 5.3 shows a simple electrical generator. N S a.c. output slip rings coil Fig. 5.3 (i) Explain why a voltage is induced in the coil when the coil is turned. [1] (ii) Explain why this generator produces an alternating current. [1]

12 © UCLES 2010 0653/32/O/N/10 For Examiner's Use 6 A solution of sodium chloride is produced when sodium hydroxide solution, an alkali, is neutralised by dilute hydrochloric acid. Fig. 6.1 shows apparatus which can be used to carry out this neutralisation. conical flask containing sodium hydroxide solution burette containing dilute hydrochloric acid tap which allows acid to be run slowly and carefully into the conical flask Fig. 6.1 (a) Complete the balanced symbolic equation, involving ions and molecules, for the neutralisation reaction between an aqueous acid and an aqueous alkali. H+ + → [2] (b) A student adds a few drops of litmus solution, an indicator, to the sodium hydroxide solution. Suggest what the student should then do in order to produce a neutral solution of sodium chloride, using only the apparatus shown in Fig. 6.1. [2] (c) Suggest how the student could use information gained from the experiment in (b) to obtain a sample of dry, colourless sodium chloride crystals which do not contain any litmus. [3]

13 © UCLES 2010 0653/32/O/N/10 [Turn over For Examiner's Use 7 (a) Polar bears live in the cold, arctic region. They have thick, white fur. (i) Describe how fur keeps a polar bear warm. [2] (ii) Explain why white fur will keep a polar bear warmer than black fur. [2]

14 © UCLES 2010 0653/32/O/N/10 For Examiner's Use (b) An elephant can communicate with other elephants using infra-sound. This is a very low frequency vibration, which is usually impossible for a human to hear. (i) Suggest a possible frequency for this vibration and explain how you chose your answer. frequency Hz explanation [1] (ii) State the meaning of the term frequency. [1] (iii) Fig. 7.1 shows an oscilloscope trace for a low frequency sound which the human ear can just hear. Fig. 7.1 On Fig.7.2 draw the trace of an infra-sound wave of the same amplitude. [2] Fig. 7.2

15 © UCLES 2010 0653/32/O/N/10 [Turn over For Examiner's Use (c) Fig. 7.3 shows a magnifying glass being used to look at a caterpillar. 1.6 cm 0.8 cm 1.0 cm magnifying glass Fig. 7.3 (i) State the focal length of the lens. [1] (ii) Complete the ray diagram to show how the eye sees an enlarged image of the caterpillar. [2] (iii) This image is called a virtual image. Explain the meaning of the term virtual image. [1]

16 © UCLES 2010 0653/32/O/N/10 For Examiner's Use 8 Carbon and hydrogen combine to form hydrocarbons. Ethene, C2H4, is a gaseous, unsaturated hydrocarbon, which is of industrial importance. (a) Complete the displayed formula of the ethene molecule which has been started below. H C [2] (b) Unsaturated hydrocarbons are made in industry from fractions obtained by the fractional distillation of oil (petroleum). Name the process which is used to make unsaturated hydrocarbons, and describe briefly how it is done. name of process description [3] (c) Describe, in terms of changes to chemical bonds, what happens when ethene molecules react to form molecules of poly(ethene). [2]

17 © UCLES 2010 0653/32/O/N/10 [Turn over For Examiner's Use (d) Calculate the relative formula mass of ethene. Show your working. [2]

18 © UCLES 2010 0653/32/O/N/10 For Examiner's Use 9 A healthy plant growing in a pot was watered and placed in a sunny window. A transparent plastic bag was placed over the plant, as shown in Fig. 9.1. soil pot transparent plastic bag Fig. 9.1 (a) The temperature near the window fell overnight. The next morning, small droplets of water were visible on the inside of the plastic bag. Explain why the droplets of water appeared on the inside of the plastic bag. [4]

19 © UCLES 2010 0653/32/O/N/10 [Turn over For Examiner's Use (b) The plastic bag was then removed from the plant. The next day was warm and sunny, and by the end of the day the plant had lost so much water that it wilted. Fig. 9.2 shows a cell from a leaf before and after the plant wilted. before wilting after wilting Fig. 9.2 (i) On the diagram of the cell before wilting in Fig. 9.2, label and name two structures that would not be present in an animal cell. [2] (ii) Using your knowledge of osmosis, explain what happened to the plant cell to cause its appearance after the plant wilted. [3]

20 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. © UCLES 2010 0653/32/O/N/10 Group 140 Ce Cerium 58 141 Pr Praseodymium 59 144 Nd Neodymium 60 Pm Promethium 61 150 Sm Samarium 62 152 Eu Europium 63 157 Gd Gadolinium 64 159 Tb Terbium 65 162 Dy Dysprosium 66 165 Ho Holmium 67 167 Er Erbium 68 169 Tm Thulium 69 173 Yb Ytterbium 70 175 Lu Lutetium 71 232 Th Thorium 90 Pa Protactinium 91 238 U Uranium 92 Np Neptunium 93 Pu Plutonium 94 Am Americium 95 Cm Curium 96 Bk Berkelium 97 Cf Californium 98 Es Einsteinium 99 Fm Fermium 100 Md Mendelevium 101 No Nobelium 102 Lr Lawrencium 103 1 H Hydrogen 1 7 Li Lithium 3 23 Na Sodium 11 24 Mg Magnesium 12 40 Ca Calcium 20 45 Sc Scandium 21 48 Ti Titanium 22 51 V Vanadium 23 52 Cr Chromium 24 55 Mn Manganese 25 56 Fe Iron 26 59 Co Cobalt 27 59 Ni Nickel 28 64 Cu Copper 29 65 Zn Zinc 30 70 Ga Gallium 31 27 Al Aluminium 13 11 B Boron 5 12 C Carbon 6 14 N Nitrogen 7 16 O Oxygen 8 19 F Fluorine 9 28 Si Silicon 14 31 P Phosphorus 15 32 S Sulfur 16 35.5 Cl Chlorine 17 40 Ar Argon 18 20 Ne Neon 10 4 He Helium 2 73 Ge Germanium 32 75 As Arsenic 33 79 Se Selenium 34 80 Br Bromine 35 84 Kr Krypton 36 39 K Potassium 19 88 Sr Strontium 38 89 Y Yttrium 39 91 Zr Zirconium 40 93 Nb Niobium 41 96 Mo Molybdenum 42 Tc Technetium 43 101 Ru Ruthenium 44 103 Rh Rhodium 45 106 Pd Palladium 46 108 Ag Silver 47 112 Cd Cadmium 48 115 In Indium 49 119 Sn Tin 50 122 Sb Antimony 51 128 Te Tellurium 52 127 I Iodine 53 131 Xe Xenon 54 137 Ba Barium 56 139 La Lanthanum 57 * 178 Hf Hafnium 72 181 Ta Tantalum 73 184 W Tungsten 74 186 Re Rhenium 75 190 Os Osmium 76 192 Ir Iridium 77 195 Pt Platinum 78 197 Au Gold 79 201 Hg Mercury 80 204 Tl Thallium 81 207 Pb Lead 82 209 Bi Bismuth 83 Po Polonium 84 At Astatine 85 Rn Radon 86 Fr Francium 87 227 Ac Actinium 89 9 Be Beryllium 4 I II III IV V VI VII 0 85 Rb Rubidium 37 133 Cs Caesium 55 226 Ra Radium 88 The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.). a X b a = relative atomic mass X = atomic symbol b = proton (atomic) number Key *58-71 Lanthanoid series 90-103 Actinoid series DATA SHEET The Periodic Table of the Elements

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the October/November 2010 question paper for the guidance of teachers 0653 COMBINED SCIENCE 0653/32 Paper 3 (Extended Theory), maximum raw mark 80 This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes must be read in conjunction with the question papers and the report on the examination. • CIE will not enter into discussions or correspondence in connection with these mark schemes. CIE is publishing the mark schemes for the October/November 2010 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses. www.XtremePapers.com

Page 2 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0653 32 © UCLES 2010 1 (a) idea of restoring full / correct number (of 46) in the zygote ; [1] (b) (i) ovary ; [1] (ii) oviduct / Fallopian tube ; [1] (c) produces / contains, amniotic fluid ; protects / supports, embryo ; [2] (d) (i) T, because Tt does not have thalassaemia / owtte ; [1] (ii) phenotypes of parents genotypes of parents gametes man without thalassaemia Tt and woman without thalassaemia … and gametes from woman gametes from man Tt T t T t T T t t TT Tt Tt tt thalassaemia parental genotype ; gamete genotypes ; offspring genotypes ; child with thalassaemia identified ; [4] (iii) haemoglobin transports oxygen / person with thalassaemia has less oxygen (in blood) ; so less respiration (in cells) / description of respiration ; which releases energy ; [2 max] [Total: 12] Tt

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0653 32 © UCLES 2010 2 (a) (i) pink / orange / brown / copper (layer) ; [1] (ii) 2+ ; two negative charges from chloride must balance the charge on the copper ion / owtte ; [2] (iii) (L) it is a negative ion / has a negative charge / has more electrons than protons ; reference to attraction between opposite charges ; [2] (points separately marked) (iv) one shared pair ; all other electrons correctly shown ; [2] (b) (i) carbon dioxide ; [1] (ii) 2PbO + C → 2Pb + CO2 ;; (correct formulae and balanced) [2] [Total: 10] 3 (a) (i) description charge range in air ionising ability alpha helium nucleus positive 5 cm very strong beta electron negative 50 cm medium gamma electromagnetic wave none many kilometres weak (the wording for ionising ability must show beta lies between alpha and gamma) ;;;; [4] (ii) alpha particles have low penetration in air / absorbed by casing / will not reach people living in house / smoke detectors are a long way from people ; [1] (b) working (on graph or numerically) ; 5 hours ; [2] [Total: 7]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0653 32 © UCLES 2010 4 (a) terracing / building of walls (qualified) ; bunds / embankments / ditches ; plough along slope (not up and down) ; keep crop cover ; plant trees ; [max 2] (b) (i) advantage kills more pests / can completely destroy pest population / faster acting ; does not introduce a (potentially) damaging new organism (to the ecosystem) ; disadvantage may kill other beneficial / all insects / toxic to humans / have to apply several times / development of resistance ; bioaccumulation / persistence provided related directly to DDT ; (ignore refs to costs unless related to reason) (1 max for advantage, 1 max for disadvantage) [2] (ii) meaning absorbed (by plant) and transported (in phloem) ; reaches all parts of plant ; advantage can kill pests even if it does not directly hit them ; only affects insects feeding on the plant ; [2] (1 max for advantage, 1 max for disadvantage) [Total: 6] 5 (a) (i) K and L ; [1] (ii) J lights up / on ; K and L go off ; [2] (b) 2 × 12 Ω resistors ; in parallel ; calculation to show this ; [3] (c) (i) coil cuts magnetic field / coil experiences changing magnetic field ; [1] (ii) direction of magnetic field relative to coil changes (every half turn) / direction of motion of coil through magnetic field changes / reverses ; [1] [Total: 8]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0653 32 © UCLES 2010 6 (a) (H+ +) OH– → H2O ;; [2] (b) (acid is added) until indicator / solution changes colour ; colour change correct – allow blue to either red or reasonable intermediate ; [2] (c) no indicator added / use of pH meter to show neutrality ; ref. to same amount / volume of sodium hydroxide solution / alkali (as in (b)) ; ref. to same amount / volume of acid (as in (b)) ; evaporate / heat / boil off the water (from the solution) ; [max 3] [Total: 7] 7 (a) (i) traps layer of air ; acts as insulator / reduces convection and conduction ; [2] (ii) white surfaces radiate less heat than black surfaces ; less heat is lost ; [2] (b) (i) below 20 Hz ; lowest frequency of human hearing is 20 Hz / below range of human hearing ; [1] (ii) (number of) waves / oscillations produced per unit time / wavelengths passing a point per unit time ; [1] (iii) waves have same amplitude ; less waves shown on trace ; [2] (c) (i) 1.6 cm ; [1] (ii) both rays drawn backwards to meet ; image labelled / clearly and unambiguously visible on diagram ; [2] (iii) image which cannot be projected (onto a screen) / light (rays) does not pass through it ; [1] [Total: 12]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0653 32 © UCLES 2010 8 (a) H C H H C H ;; (2C and 4H bonded and double bond shown) [2] (b) (catalytic / thermal) cracking ; fractions are boiled / vaporised / heated ; passed over (hot) catalyst / subjected to very high temp. and pressure ; (allow named catalyst e.g. alumina, silica, pumice, porcelain) [3] (c) double bonds become single ; single bonds form between molecules to form a long chain ; [2] (marks can be obtained by clear diagrams) (d) Ar C = 12 and H = 1; (12 × 2) + (1 × 4) = 28 ; [2] [Total: 9] 9 (a) water vapour lost from plant(’s leaves) ; correct ref. to transpiration ; condensation ; water vapour cooled ; gas changed to liquid ; ref. to particles and (kinetic) energy ; [max 4] (b) (i) [max 2] cell wall ; vacuole ; chloroplast ;

Page 7 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2010 0653 32 © UCLES 2010 (ii) water moved out of the cell ; down a water potential gradient / from where there was a lot of water to where there was less / from dilute solution to concentrated solution ; through partially permeable cell membrane ; so volume of cell / vacuole shrank ; strong cell wall cannot change shape (much) so cytoplasm / cell membrane pulls away from it ; [max 3] [Total: 9]